[Galerkin Closure is a General Concept]
We emphasize that, although our discussion focuses exclusively on ROMs, the Galerkin closure is a general concept that is associated with the classical Galerkin framework.
Thus, there is no surprise that, over half a century, closure has been addressed in different contexts:
large eddy simulation (LES) [1]},
variational multiscale (VMS) methods [2]},
subgrid-scale (SGS) methods [3]}, [4]},
and nonlinear Galerkin (NG) methods [5]}.
